There is a need for a system and method of accurately and economically measuring torque in a high speed rotating shaft system. There is a need for an economically feasible method of dynamically measuring torque in a high speed rotating shaft system. There is a need for a robust system and method of measuring torque of a rotating drive shaft coupling in the propulsion system of a fixed wing vertical short take off and landing aircraft vehicle, such as for monitoring a fixed wing vertical short take off and landing aircraft vehicle rotating drive shaft propulsion system flexible coupling.